FAMILY, I— SILURID^. 463 



barbels. Whether the serrations along the occipital ridge are merely due to the specimen being young is 

 questionable. 



Habitat. — Sind, from whence the single specimen, figured life-size, was brought. 



12. Arius thalassinus, Plate CIV, fig. 4, and Plate CVI, fig. 1. 



Sagriis thalassimis, Riipp. N. W. Fische, p. 75, t. 20, f. 2. 

 Bagrus bilineatus and netmna, Cuv. and Val. xiv, pp. 434, 438, pi. 417. 



Arius nasutus, Cuv. and Val. xv, p. 60 : Bleeker, Verb. Bat. Gen. xxi, Silur. Batav. p. 31 {adult). 

 Arius netuma, Bleeker, Beng. en Hind. p. 56. 



Netmna nasuta, Bleeker, Prod. Silur. p. 95, and Atl. Ich. Silur. t. 61. 

 Netuma thalassina, Bleeker, 1. c. p. 28. 



Arius thalassinus, Giinther, Catal. v, p. 139 ; Kner, Novara Fische, p. 310 ; Klunz. Verb. z. b. Ges. 

 Wien, 1871, p. 589. 



Arius Andamanensis, Day, Proc. Zool. Soc. 1870, p. 699. 



B. vi, D. I I 0, P. 1/12, V. 6, A. 15-17 {^zW, C 17. 



Length of head 4|- to 5, of caudal 5, height of body b\ to 6 in the total length. Hijes — longest diameter 

 obliquely transverse, 5 in the length of the head, 1^ to If diameters from the end of snout, and '2\ to 3 apart. 

 Width of head equals its length behind the angle of the mouth, it is broader than high. Upper surface 

 of the head granulated : the median longitudinal groove, which is narrow posteriorly, extends to opposite the 

 hind edge of the opercle. The occipital process is granulated, keeled, rather longer than wide at its 

 base, it extends to the basal bone of the dorsal fin, which is small and crescentic in shape. Barbels — the 

 maxillary extend nearly or quite to the base of the pectoral fin, the outer mandibular are a little shorter. 

 Teeth — on the palate villiform, those of each side forming a triangle composed of three patches, two in front 

 and a larger one behind (PI. civ, fig. 4 ft). Fins — dorsal spine as long as the head without the snoiit, 

 or even a little longer, granulated anteriorly (with some serrations in the young), serrated posteriorly : base of 

 adipose dorsal 2/5 of that of the rayed fin. Pectoral spine strong, but a little shorter than that of the dorsal, 

 rough externally, feebly serrated internally : caudal with the upper lobe usually the longer. Colours — ■ 

 silvery, darkest superiorly : the upper half of the adipose dorsal black. In some specimens the dorsal surface 

 is of a rich brown, and each of the granules on the head appears to be tipped with gold. 



In a stufl'ed specimen 27 inches in length the snout is much produced, a condition apparently normal in 

 the adult of this species, the eye is 8 in the length of the head and situated in the commencement of 

 the anterior half of the head. The teeth on the palate form an undivided patch. 



Habitat. — From the Red Sea, through those of Africa and India to the Malay Archipelago and beyond, 

 entering tidal rivers. It attains a large size. The specimen figured is 11 inches long, and from the 

 Andamans. 



B. Globular teeth on the palate. 



13. Arius Buchanani, Plate CV, fig. 6. 

 Pimelodus arius, Ham. Buch. Fish. Ganges, pp. 170, 376. 



B. vi, D. i I 0, P. 1/10, V. 6, A. 22 (^^V), C. 17. 



Length of head 4f, of caudal 5|-, height of body 5|- ia the total length. J7(/('.s— diameters 5j in 

 the length of head. If diameters from end of snout, and 2y apart. Greatest width of the head equals its 

 length behind the angle of the mouth. Upper jaw the longer, width of the gape of the mouth 3/8 of the length 

 of the head. Median longitudinal groove on the head rather shallow, and does not reach the base of 

 the occipital process. Upper surface of the head lineated in roughened lines, which are rather close together 

 on the occipital process, which latter is scarcely keeled, and as wide at its base as it is long. Opercle 

 higher than wide. Barbels — the maxillary ones reach to the first third of the pectoral fin, the outer 

 mandibular ones almost to its base. Teeth — on the palate in two oval patches, one on either side, each as large 

 as the eye, placed far back and parallel to one another, the teeth have large globular heads. Fi)is — 

 dorsal higher than the body, its spine as long as the head behind the angle of the mouth, anteriorly roughened 

 in its lower two-thirds, and serrated in its upper, posteriorly very feebly serrated : base of tlie adipose dorsal 

 3/4 of that of the rayed fin. Pectoral reaches the base of the ventral, the spine is stronger than that 

 of the dorsal but of equal length, it is serrated on both sides. Ventral almost reaches the anal ; iTpper caudal 

 lobe the longer. Colours — silvery along the back, lighter on the sides and below, pectoral and dorsal 

 edged posteriorly with blackish : adipose dorsal with a well defined black spot. 



Habitat. — Hooghly at Calcutta and Burma. The specimen figured was from the Irrawaddi. 



14. Arius falcarius, Plate CVI, fig. 5. 



.'' Arius arius, Cuv. and Val. xv, p. 102 ; Bleeker, Beng. en Hind. p. 56, pt. not Pseiidarius arius, 

 Bleeker. 



Arius falcarius, Richardson, Voy. Sulphur, Fish. p. 134, pi. 62, fig. 7-9. 

 Bagrus crinalis and mong, Richardson, Ich. China, pp. 282, 286. 

 Arius Schcgelii, Bleeker, Ned. Tyds. Dierk. 1863, p. 146. 



